x_1,y_1,x_2,y_2=map(float,input().split())

import math
x=(x_2-x_1)**2
y=(y_2-y_1)**2

l=math.sqrt(x+y)
print('{:.16g}'.format(l)) x_1,y_1,x_2,y_2=map(float,input().split()) x_1 map(float,input().split()) map float input().split() ().split () input split y_1 x_2 y_2 import math math x=(x_2-x_1)**2 x (x_2-x_1)**2 x_2-x_1 x_2 x_1 2 y=(y_2-y_1)**2 y (y_2-y_1)**2 y_2-y_1 y_2 y_1 2 l=math.sqrt(x+y) l math.sqrt(x+y) math.sqrt math sqrt x+y x y print('{:.16g}'.format(l)) print '{:.16g}'.format(l) '{:.16g}'.format '{:.16g}' format l x_2,y_2=map(float,input().split()) map(float,input().split()) x_2 y_1,x_2,y_2=map(float,input().split()) map(float,input().split()) y_1 y=(y_2-y_1)**2 (y_2-y_1)**2 y x=(x_2-x_1)**2 (x_2-x_1)**2 x y_2=map(float,input().split()) map(float,input().split()) y_2 l=math.sqrt(x+y) math.sqrt(x+y) l x_1,y_1,x_2,y_2=map(float,input().split()) map(float,input().split()) x_1
x_1,y_1,x_2,y_2=map(float,input().split())

import math
x=(x_2-x_1)**2
y=(y_2-y_1)**2

l=math.sqrt(x+y)
print('{:.16g}'.format(l))
